Project Background: Currently, hundreds of thousands of veterans receive housing and associated services (mental health treatment, job training) through several VA homeless programs. These programs vary in the type of housing support they provide (e.g., transitional, domiciliary, permanent) and in associated services they offer. Surprisingly, there is no assessment that is routinely used in VA programs that examines characteristics of veteran history and current functional status, providing interpretable results to optimize outcomes. For many years the VA homeless programs have collected program evaluation questionnaire data. These data (e.g., the standardized intake evaluation form titled Form X) do capture information that would appear to be relevant to intervention decisions (e.g., length of time without residence, health and mental health problems), but are not transformed into reliable, valid indices for use in decision-making. For example, Form X requires the intake clinician to ask five questions about alcohol use, but this information is not then transformed into an index that would serve as an estimate of severity of use/abuse, predict outcomes, or drive decisions about treatment. Project Objectives: The overall objective of the proposed study is to develop a multiscale structured interview (the Homelessness Severity Index, HSI) that will provide a comprehensive, informative evaluation of homeless status at the point of first contact with care providers. Our specific objectives are to: 1) refine the set of domains or factors influencing the occurrence and chronicity of homelessness (e.g., psychosocial characteristics, comorbid conditions), 2) expand and refine the items tapping elements of each of the identified domains, and 3) create index subscales that will provide estimates of severity for each of the domains. This work is modeled on the Addiction Severity Index (ASI), developed by McLellan et al. (1980, 1992). The ASI is a structured interview that provides estimates of addiction severity in seven domains (e.g., drug problems, medical problems). Developed largely in VA programs, the ASI is one of the most widely used instruments in the field of substance abuse and has been used in numerous studies of treatment outcome. In this proposed study, scale development and initial validity research will use a similar methodological approach as that used in establishing the ASI. The proposed research is enhanced by the availability of substantial numbers of potential homeless veteran participants (the PI is national director of the largest VA homeless program, the Grant and Per Diem program) and by prior experience in scale development (the co-Investigator has extensive experience in scale development and validation). Project methods: A rational-empirical method of scale development will be used to develop the HSI. The method will require the following sequential steps: 1) creation of pool of interview items tapping relevant domains identified in homelessness risk research (e.g., work/finances, alcohol use), 2) refinement of the item pool via review by a panel of expert judges (clinicians experienced in the field of homelessness) to create an alpha version, 3) administration of the alpha version of the HSI to veterans applying to homeless programs (under an approved VA/IRB protocol), 4) item analyses and scale refinement using Mokken scaling analysis methods as well as examination of traditional multiple psychometric criteria (e.g., item-total scale and cross- scale correlations, squared multiple correlations, conditional alpha on item deletion), 5) establishment of internal reliability and examination of factor structure, 6) development of scoring algorithms for individual scales and the total index, and 7) examination of contrasted groups performance and convergent/discriminant correlations with demographic variables to establish initial validity. Subsequent funding will be requested to refine and validate the HSI for use across homeless programs and subpopulations.